The present invention concerns a method for authenticating/identifying secure biometric data.
1. Field of the Invention
An explanation of the authentication method is given in the rest of the text for the purposes of simplification.
The invention also concerns a biometric data input module and a module for verifying said data making it possible to implement the method, the cooperation of these two modules forming part of the embodiment of an authentication system.
The invention is applicable specifically to the field of biometric authentication or identification with verification by a device placed some distance away via a communication network.
A biometric data entry module is understood to be any device, such as a biometric sensor, making it possible to record the biometric elements of a user of the authentication system.
A biometric data verification module is understood to be any device able to process the biometric information so as to verify it and its authenticity. It can be a data processing computer or a specific electronic card placed in a processing system.
2. Description of the Related Art
The patent published on 23 Jul. 1998 under the number WO98/32093 describes a method for preventing the replay of the biometric data.
Replay is understood to be any ill-disposed action consisting of capturing the biometric data of a user of the authentication system so as to send said data to the verification device and thus claim to be said user.
The method describes in this application is based on the fact that the characteristic biometric elements, also called “minutiae” never have the same value between two inputs. The method described is limited in the fact that it needs to store the “minutiae” received from preceding authentication and identification tests and in the fact that it is unable to take precautions against replayed data after having been slightly modified deliberately so as to cheat the system.
There are also systems able to implement a biometric method with remote verification of the minutiae and thus the sending of data via a communication network.
In this case, either the solutions put forward do not take into account the problems linked to theft and the replay of data or they associate cryptographic secrets in the various modules of the system. For example, it is possible to find this solution on the patent application published on 06 Nov. 1998 under the number WO/9825385. In fact, the method described in this patent protects the data from being overheard on the line but is unable to prevent the replay of said data. The two communicating modules have available a pair of private keys.
In the case of secrets present in the various modules of the system, there is a risk that the secrets stored in these various modules may be stolen. The theft of the secret(s) stored in the various modules can bring about the actual theft of the modules themselves and in particular of the biometric input module which is placed to be accessible by the public.
However, in certain existing solutions, the modules and in particular the biometric input module are not designed to memorise the secret internally, but it is necessary when the secret is provided by the user by means for example of a smart card or badge.
These systems are described for example in the patent application published on 24 Mar. 1999 under the number GB 2329499 or in the patent application published on 13 Feb. 1997 under the number WO97/05578.
With the solution of this last-mentioned document, the simplicity of use and the ergonomics of the biometry becomes indistinct since the user wears or carries a physical tool (a smart card or a badge).